Poor air quality is the most severe environmental hazard to people globally. To improve the accuracy of urban air quality predictions, better models and air quality measurement networks are needed. The Helsinki metropolitan Air Quality Testbed (HAQT) project demonstrated an end-to-end approach to meet this demand by adding cost efficient air quality instruments to the current reference network in the Helsinki metropolitan area, and by using that data as input to ENFUSER model to significantly improve air quality forecasts in the Helsinki metropolitan area and surroundings, and finally by implementing a few demo services for data dissemination.
In HAQT, the reference-level air quality monitoring network in the Helsinki metropolitan area by HSY was supplemented by two types of commercial air quality instruments. The added value of these supporting and affordable air quality instruments, when used within an air-quality monitoring network, was investigated using the ENFUSER modelling system. The ENFUSER assimilated the most recent environmental information for the assessment of urban air quality in a high resolution based on local sensor network, regional air quality maps, meteorological data and a collection of GIS-datasets. Besides high-resolution nowcasts and forecasts for local air quality, the ENFUSER offered diagnostics for the assessment and fine-tuning of the sensor network supplying the model. These overarching objectives were performed by using the installed set of a large number of affordable AQ equipment connected with the CityzerDEMO network.